Formation of pea protein amyloid fibrils to stabilize high internal phase emulsions for encapsulation of lutein

Abstract

Thermal treatment of purified pea protein in acidic environment was found to induce the hydrolysis and re-assembly of the protein to form amyloid fibrils. Pea protein amyloid fibrils showed high polymorphism with the coexistence of mature and worm-like fibrils. Pea protein amyloid fibrils can stabilize the high internal phase emulsions (HIPEs) with the internal phase volume fraction as high as 90%. The gel strength of HIPEs was enhanced with the increase of pea protein amyloid fibril contents and the dispersion speed. The typical microstructure of highly packed polyhedral geometric oil droplets appeared in both the laser scanning confocal microscopy (CLSM) and Cryo-scan electron microscopy (Cryo-SEM) images of the HIPEs samples. High loading content of lutein upto 0.2 wt% in the prepared HIPEs was realized and the stability of lutein against ultraviolet irradiation, heat and iron was promoted significantly.